Centrifugal speed responsive apparatus having spring supported weights



June 15, 1954 R M PURDY ETAL 2,681,220

CENTRIFUGAL SP EED RESPONSIVE APPARATUS HAVING SPRING SUPPORTED WEIGHTS Filed May 26, 1950 FIG. I.

INVENTORS Wm? WWZ ATTORNEY Patented June 15, 1954 CENTRIFUGAL SPEED RESPONSIVE AP- PAR-ATUS HAVING SPRING SUPPORTED WEIGHTS Rolland M. Purely and Harald ltiainusch, Bainbridge, N. Y., assignors to Bendix Aviation Corporation, New York, N. Y., a corporation of Delaware Application May 26,

Claims.

This invention relates to speed responsive apparatus and more particularly to devices responsive to centrifugal forces created by rotating parts.

One of the objects of the present invention is to provide a novel centrifugally actuated means adapted for use in controlling the functioning of other apparatus in accordance with the speed of a rotating member.

Another object of the invention is to provide novelly constructed means operable in accordance with the speed of a rotating part.

Still another object is to provide novel speed responsive apparatus adapted to be operatively combined with a rotating shaft without interfering with the transmission of power by the shaft.

A further object is to provide novel centrifugally actuated apparatus for imparting linear or axial movement to a part rotatable therewith.

A still further object is to provide apparatus of the above character which structurally speaking is the essence of simplicity whereby manufacturing and maintenance costs are minimized and operating efflciency is enhanced.

Another object is to provide a novel and simpliiied speed responsive device which may be readily adjusted for operation at different speeds.

The above and further objects and novel features of the invention will more fully appear from the following detail description when the same is read in conjunction with the accompanying drawing. It is to be expressly understood, however, that the drawing is for the purpose of illustration only and is not intended as a definition of the limits of th invention.

In the drawing wherein like reference characters refer to like parts throughout the several views,

Fig. 1 is a side elevation View showing one embodiment of the invention adapted for use in controlling the transmission of a vehicle, for example, in accordance with the speed of the vehicle;

Fig. 2 is a sectional side elevation View of one type of centrifugally controlled circuit breaker unit adapted for use in the structure shown in Fig. 1, the section being taken substantially on line 2-2 of Fig. 1;

Fig. 3 is a transverse sectional view with parts broken away, the section being taken substantially on line 3-3 of Fig. 2;

Fig. 4 is an isometric view, partly in section and with parts broken away, the View being taken from the left in Fig. 2 with the casing cover removed; and,

1950, Serial No. 164,552

Fig. 5 is a detail exploded isometric view of some of the parts or said unit.

The single embodiment of the invention illus trated in the drawing, by way of example, is in the form of a control unit adapted for use in conjunction with the speedometer of a motor vehicle or the like to control the operation of an electrical switch in accordance with the speed of the vehicle. The switch may, for example, control a circuit to an electrically operated means for controlling the transmission or other functional apparatus on the vehicle (not shown) in a desired manner and in accordance with variations in vehicle speed. For example, the control means may be operative to effect shifting of the transmission from one gear ratio to another and. back again at different predetermined vehicle speeds. As a more specific example, the present device may eifect a shift into so-called overdrive in modern automobiles at one vehicle speed and a shift back to regular drive at a lower predetermined vehicle speed. The unit may, of course, be operatively associated with any other rotating part to effect control in accordance with the speed of rotation of the part.

As shown in Fig. 1 the novel control unit it is operatively associated with a speedometer H which may be of th type extensively used on automobiles, trucks and like Vehicles, the same being operatively driven from an engine or vehicle driven part (not shown) which rotates at a speed proportional to the speed of the vehicle. The transmission of power from the driving part may be through a flexibl shaft it housed in a flexible armor l2 and through the novel control unit. The latter is provided with a through shaft It which is operatively connected at one end to the flexible driving shaft H5 in the same manner that the latter is usually connected with the speedometer itself. For example, the square end of the driving shaft extends into a squared recess It in shaft is and the square end I? of shaft it extends into a squared recess in a rotating part of a speedometer in the usual manner.

As shown in Figs. 1 to 3, the control unit l0 comprises the rotating shaft ii-l3 which is journalled in a flanged stationary supporting member It. Axial movement of the shaft relative to the support may be prevented by providing a collar 26 on the shaft and flaring the hollow end thereof as shown at 2 l. The operating parts may be enclosed by a cup-shaped cover or casing member 22 which may be removably secured to flanged support l9 and to the speedometer casing by a nut 23 surrounding shaft I 1.

Th snap-action device or switch embodied in the present invention consists wholly of nonrotatable parts and in the specific form shown, by way of example, comprises a stationary contact 2&- on a bracket 25 of electrically conductive material. The latter is mounted. on and suitably insulated from support member l9 by means including a rivet 26 and a terminal screw 2'5 which extends through the support for connection with a lead 28 externally of easing i9, 22. The lead may be part of a circuit including an electrical device such as solenoid, for example, and a source of electrical energy, such as a battery or other source. A movable contact carrying member 29 carries a contact 31 and is mounted for substantially frictionless pivotal movement relative to the supporting member l9.

For mounting member 29 and for limiting movement thereof in one direction, a bracket St is secured to support is in some suitable manner,

such as by rivets. The supporting member may have a recess 32 therein for this purpose. The end of the upstanding portion of bracket 35 nearest shaft 66 and the corresponding end of contact carrying member 29 are centrally slotted or bifurcated to straddle a spring 33, the function and operation of which will be hereinafter fully described. Any suitable known method of pivotally mounting member 29 on bracket as may be used, and as shown the ends 3:3 of the arms or bifurcations of the bracket are of reduced width and bent to form bites or notches in which the bifurcations or arms of member 29 are loosely received. Lateral movement of said member in the direction of the axis of shaft It is prevented by extensions on member 29 which straddle the bent ends 34 in the manner best illustrated in Fi 4.

Movement of the contact carrying member 29 between its limiting positions against brackets 25 and 3b is effected by spring 33 and a pivoted actuating member 35. The latter is journaled for free pivotal movement about a boss on support it and is secured in position by a screw or rivet. The pivotal axes of members 251 and 35 are located on a line which extends between brackets 25 and 3t and hence between the extreme or stop positions of contact member 29. Member 35 is formed with two arms or bifurcations 35 and 3'5 that straddle shaft 16, the arm extending into the vicinity of the pivotal axis of member 29 and being connected to the inner end of spring 33. Since the arm 31 is cut off by the section in Fig. 2, the same is illustrated in phantom or dotted lines in said figure in the interest of clarity.

The construction is such that when arm 36 is moved to the full line position illustrated in Figs. 3 and 4, spring 33 will pivot contact member 29 in a clockwise direction, as viewed in Fig. 3, with a quick snap-action and then resiliently press contact 3i into engagement with stationary contact it. An electrical circuit will thus be completed through said contacts, lead 28, and ground or such other return lead as may be connected to contact 3!. When arm 36 is moved to the dotted line position shown in Fig. 3, thereby moving the end of spring 33 to the right and past pivot 36', the line of action of the spring becomes such that toggle member 29 will be snapped to the right in a counter-clockwise direction into engagement (dotted line position) with bracket til, thereby breaking the circuit at contact 2d.

The necessary pivoted movement of forked member 35 is effected in a novel manner in accordance with and in response to the speed of shaft 15 by means rotatable with said shaft and cooperable in a novel way with said member. In the form shown arm 37 has a bend 38 therein so that the end portion thereof adjacent shaft is is in a different transverse plane than the corresponding portion of arm 36, i. e., a different plane perpendicular to the axis of rotation of the shaft. Surrounding an enlarged portion of shaft it adjacent support member 19 is a sleeve 39 which has a cam lobe or lug lfi projecting from the outer surface thereof for cooperation with lever arms and 31 in a manner to hereinafter more fully appear.

Suitable means are provided for causing sleeve 35! to rotate with shaft i6 and to move axially thereon in response to the speed of shaft 53. As illustrated said means are of the centrifugally actuated type and comprise a leaf spring 41 mounted on shaft It for rotation therewith. The driving connection may be effected by providing a rectangular hole in the spring to fit the squared portion ll of the shaft. Spring ii may be fixedly or adjustably secured against axial movement on shaft 16 in any suitable known manner, resilient lips or tongues til at the ends of the opening in the spring being employed for this purpose in the illustrated embodiment. The tongues resiliently engage the shaft and prevent unintentional or accidental movement of the spring axially away from the shoulder on shaft is formed by the enlarged cylindrical portion thereof within sleeve 39. In another suitable embodiment a washer having portions thereof staked or spread into grooves in the shaft is used to secure the spring against said shoulder.

The end portions of spring 3! are inclined away from sleeve 39, the same making an acute angle with the axis of shaft rotation. A loop or bite is formed at each end of spring ll for resiliently gripping and supporting a flanged or spool-like weight member 43. Thus, when the shaft rotates with spring ll and weights 43, centrifugal force which is proportional to speed tends to throw the weights away from the axis of rotation and hence, to bend the ends of the spring G1 to the, right, as viewed in Fig. 2, toward a position perpendicular to said axis. Adjustments to get desired operation may be readily made by bending spring :33 to change the initial angle of the arms thereof. Similar results may be effected by increasing or decreasing the mass of weights 43.

This motion, which is thus centrifugally imparted to spring 4|, and the rotary movement thereof are transmitted to cam sleeve 39 through a rigid member 44 having oppositely extending inclined arms. The latter are preferably spaced a short distance from the corresponding arms of spring 4i and extend between the flanges of weight members 13, whereby the rotary movement of the shaft is imparted to motion transmitting member 44 through spring 4i and weights 33. The central flat portion of member 44 has an oblong opening 45 (Figs. 4; and 5) and the end of sleeve 39 has portions thereof cut away (Fig. 5) to make it fit into said oblong opening and thereby effect a rotary driving connection between member M and sleeve 39.

The rigid arms of member 44 operatively engage the inclined ends of spring fil so that flexing of the latter in response to centrifugal force will move member id and hence sleeve 39 axially along shaft 55. Such engagement or its equivalent may be effected in various ways, such as by pressing a bead 46 in each of said arms to make 5 substantially point contact with the spring and hence minimize friction. The outer or free ends of rigid arms fi l, t l may be curved as best seen in Fig. 2 to limit the movement of weights radially from the shaft.

It will thus be seen that as the arms of spring 4! are response to centrifugal force, member and sleeve 39 will be moved bodily to the right (Fig. 2). This axial movement of sleeve is yieldably resisted by suitable resilient means such as a coil spring 4? (Fig. 2) surrounding shaft 55 between collar 2i! and an internal shoulder in sleeve 39. Beads it may be replaced by adjustable set screws or the like in arms 44, whereby the speed at which spring ll will engage and start to move member as may be readily varied or adjusted. Adjustment could also be effected by providing means to change the initial compression of spring 4?.

When the parts are at rest or rotating at slow speed, spring 4? urges sleeve 39 and member M to the illustrated position against spring 4! which acts as a stop. In this position, cam lobe 49 is in the plane of arm 3? so that upon rotation of the shaft, members 35 and 29 will assume their dotted line position (Fig. 3), that is open circuit position. As the speed of the shaft increases, sleeve is is moved axially toward support is in response to centrifugal force until cam lobe 40 moves into the plane of toggle arm 35 and moves the latter away from the axis of rotation to efiect a snap-action of contact member 29 into circuit closing osition (full line, Fig. l) as heretofore described. The angle between arms 36 and 3'! and the location of the snap-action device on support it) is such that when the member 35 is in full line position (Fig. 3) the arm 36 will be out of reach of the rotating cam lobe 9 and arm 37 will be sufficiently close to sleeve 39 to be engageable by the lobe when it moves into the same plane therewith. Likewise when the cam lobe has moved fork lever 35 to dotted line position (Fig. 3) the parts will be held by spring 33 so that arm 2i will be out of reach of the cam lobe and arm 36 will be close to the sleeve for engagement by the lobe when it is moved into the same plane.

As will be understood by those skilled in the art, the characteristics of the resilient means 4| and 47 which oppose the centrifugal force in this device, may be such that the axial movement of sleeve 35 will be gradual as the rotary speed increases. On the other hand, said characteristics may be such that when the initial tension or force of the springs is overcome by centrifugal I force the sleeve will move rapidly to its other extreme position without further appreciable increase in speed. In either event, the parts may be designed and adjusted so that sleeve 39 will move lobe as into the plane of arm 36 at a predetermined or selected speed of shaft is and back into the plane of arm 3? when the shaft has been slowed to a predetermined or selected lower speed. The switch 2 Si is accordingly closed at a predetermined speed of shaft '15 and remains closed at all higher speeds and until the speed is reduced to a predetermined lower speed. It is of course clearly apparent that the switch may be opened at the higher speed and caused to close at the predetermined lower speed, either by reversing the planes of levers 36 and 31, or by changing the electrical connections.

The novel structure disclosed in this application apart from the specific speed responsive means illustrated, is claimed in Walter J.

6 Spengler application Serial No. 164,553 for Governor with Over-center spring Snap-action Output filed May 26, 1950.

Although only a limited number of embodiments or modifications of the invention are illustrated in the drawing and described in the foregoing specification, it is to be expressly understood that the invention is not limited thereto. For example, the centrifugally responsive means comprehended by this invention is not limited to the specific use illustrated and herein described, but may be used for purposes other than the actuation of a snap-action device. Additionally, rotary movement may be imparted to sleeve 39 directly from shaft it if desired, such as by a or land and groove connection or by any other suitable known means. Other known means may also be provided for securing spring ill to shaft iii, 5? for rotary movement therewith and against axial movement relative thereto. Various other changes may also be made particularly in the design and arrangement of parts illustrated without departing from the spirit and scope of the invention as the same will now be understood by those skilled in the art.

What is claimed is:

l. Centrifugally responsive apparatus comprising a rotatable shaft, a unitary leaf spring secured to and rotatable with said shaft, said spring having arms extending from opposed sides of said shaft at an acute angle thereto, the outer ends of said spring arms being free and curved to the form of circular arcs exceeding 180 degrees, weight members yieldably held in and by said free curved ends, means mounted on said shaft for axial movement relative thereto including a member having rigid portions engageable by said spring arms, whereby fiexion of he latter in response to centrifugal force imparts a pushing force to move said member axially along the shaft, and resilient means resisting said axial movement of said member, said weight members being spool-shaped with end flanges which engage said axially movable member to impart rotary movement thereto.

2. In apparatus or the class described, a rotatable member, a unitary leaf spring secured to and rotatable with said member, said spring being approximately U-shaped in a plane containing the axis of rotation of said member, weights yieldably held in the curled ends of said spring for flexing the latter i response to centrifugal forces during rotation of said member, and means axially slidable on said member includ ing axially extending rigid portions engageable with and adapted to be pushed axially along said member by said spring when the latter is flexed in response to centrifugal force, the curled ends of said spring being free and said weights being spoolwhaped with said curled ends partially surrounding and engaging the neck portions thereof between the end flanges.

3. In apparatus of the class described, a rotatable member, a unitary leaf spring secured to and rotatable with said member, said spring being approximately iJ-shaped in a plane containing the axis of rotation of said member, weights yieldably held in the curled ends of said spring for flexing the latter in response to centrifugal forces during rotation of said member, said weights being spool-shaped with the curled ends of the spring around the central portions thereof between the end flanges, and means axially slidable on said member having laterally extending portions engageable with and movable axially by said spring when the latter is flexed in response to centrifugal force and engageable by the end flanges of said Weights for imparting rotary movement thereto.

4. Apparatus as defined in claim 2 including resilient means for yieldably resisting said axial movement of said axially slidable means,

5. Centrifugally responsive apparatus comprising a rotatable shaft, a unitary leaf spring secured to and rotatable with said shaft, said spring having arms extending from opposed sides of said shaft at an acute angle thereto, the free ends of said spring arms being curved, weight members yieldably held in said curved ends, means mounted on said shaft for axial movement relative thereto including a member having portions engageable by said spring arms, whereby flexion of the latter in response to centrifugal force imparts movement to said member axially along the shaft, and resilient means resisting said axial 8 movement of said member, said weight members being spool-shaped and the end flanges thereof having engagement with said axially movable member to impart rotary movement thereto.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 287,822 Gardner Nov. 6, 1883 785,126 Springer Mar. 21, 1905 1,082,225 Deardorfi Dec. 23, 1913 1,535,723 Hostetler 1 Apr. 28, 1925 2,323,791 Carrington July 6, 19 1-3 2,381,931 Shepard et a1 Aug. 14, 1945 2,493,897 Petz et al Jan. 10, 1950' 2,603,473 Harstick July 15, 1952 FOREIGN PATENTS Number Country Date 20,979 Germany Jan. 25, 1883 

